With "simpleFoam" everything was ok, but I would like to use the solver "icoFoam".
With icoFoam I took delta t = 0.00001 s, but still was not ok. I run it on a cluster, because on my notebook it lasted 8 hours to do the first 0,5 seconds.

I choosed the endTime 12.

Maybe it also could be another adjustment in icoFoam. If somebody has experience with this solver, it would be great.